Case 2:
Policy implications
of sea level rise
Measuring tides
Modern device
similar. also
measures wind
speed and
direction, water
current speed
and direction,
air and water
temperature,
and barometric
pressure.
Sea level data
Monthly observations 1959-2008, 55 sites, 6 in WA
Global mean sea level
Each point in the global mean sea
level (GMSL) time series plots is
the area-weighted mean of all of
the sea surface height anomalies
measured by the altimeter of the
TOPEX A/B satellite in a single,
10-day satellite track repeat cycle
(time for the satellite to begin
repeating the same ground track).
Difference between
gauges and satellite
Land motion
• glacial rebound (millenial scale)
• tectonic activity (decadal scale)
Altimeter drift
• orbital drift
• instrument drift
Where do the climate
model values come from?
Change in
sea level height
Cumulative change
in temperature
(slow response)
Change in
temperature
(quick
response)
Downscaling
Find a statistical relationship
between global sea level change
and local sea level change
Apply this relationship to global
sea levels estimated from
projected temperatures
Uncertainties?
Projected sea level rise
in Puget Sound
Mote et al. (2008)
Scenario
2050 SLR
2100 SLR
Very low
8 cm
16 cm
Medium
15 cm
34 cm
Very high
55 cm
128 cm
Consequences for
Olympia
Some thoughts
Not only mean sea level that
matters
Even in the very low scenario, a
combination of heavy rain, high
tide, and storm surge can cause
major damage
Not everyone is convinced that
the threat is real
...but
Dec 17, 2012, 5.4 m tide
The task
• Develop a set of policy options
regarding sea level rise for the
city of Olympia
• Produce supporting projections
of sea level rise with estimates
of uncertainty
• Present the results and some
background material on a set of
linked web pages aimed at the
general public